1 ;;; Guile RTL assembler
3 ;;; Copyright (C) 2001, 2009, 2010, 2012, 2013 Free Software Foundation, Inc.
5 ;;; This library is free software; you can redistribute it and/or
6 ;;; modify it under the terms of the GNU Lesser General Public
7 ;;; License as published by the Free Software Foundation; either
8 ;;; version 3 of the License, or (at your option) any later version.
10 ;;; This library is distributed in the hope that it will be useful,
11 ;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
12 ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 ;;; Lesser General Public License for more details.
15 ;;; You should have received a copy of the GNU Lesser General Public
16 ;;; License along with this library; if not, write to the Free Software
17 ;;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 ;;; This module implements an assembler that creates an ELF image from
22 ;;; RTL assembly and macro-assembly. The input can be given in
23 ;;; s-expression form, like ((OP ARG ...) ...). Internally there is a
24 ;;; procedural interface, the emit-OP procedures, but that is not
25 ;;; currently exported.
27 ;;; "Primitive instructions" correspond to RTL VM operations.
28 ;;; Assemblers for primitive instructions are generated programmatically
29 ;;; from (rtl-instruction-list), which itself is derived from the VM
30 ;;; sources. There are also "macro-instructions" like "label" or
31 ;;; "load-constant" that expand to 0 or more primitive instructions.
33 ;;; The assembler also handles some higher-level tasks, like creating
34 ;;; the symbol table, other metadata sections, creating a constant table
35 ;;; for the whole compilation unit, and writing the dynamic section of
36 ;;; the ELF file along with the appropriate initialization routines.
38 ;;; Most compilers will want to use the trio of make-assembler,
39 ;;; emit-text, and link-assembly. That will result in the creation of
40 ;;; an ELF image as a bytevector, which can then be loaded using
41 ;;; load-thunk-from-memory, or written to disk as a .go file.
45 (define-module (system vm assembler)
46 #:use-module (system base target)
47 #:use-module (system vm instruction)
48 #:use-module (system vm dwarf)
49 #:use-module (system vm elf)
50 #:use-module (system vm linker)
51 #:use-module (system vm objcode)
52 #:use-module (rnrs bytevectors)
53 #:use-module (ice-9 binary-ports)
54 #:use-module (ice-9 vlist)
55 #:use-module (ice-9 match)
56 #:use-module (srfi srfi-1)
57 #:use-module (srfi srfi-4)
58 #:use-module (srfi srfi-9)
59 #:use-module (srfi srfi-11)
60 #:export (make-assembler
68 ;;; RTL code consists of 32-bit units, often subdivided in some way.
69 ;;; These helpers create one 32-bit unit from multiple components.
71 (define-inlinable (pack-u8-u24 x y)
73 (error "out of range" x))
76 (define-inlinable (pack-u8-s24 x y)
78 (error "out of range" x))
84 (else (error "out of range" y)))
87 (define-inlinable (pack-u1-u7-u24 x y z)
89 (error "out of range" x))
91 (error "out of range" y))
92 (logior x (ash y 1) (ash z 8)))
94 (define-inlinable (pack-u8-u12-u12 x y z)
96 (error "out of range" x))
98 (error "out of range" y))
99 (logior x (ash y 8) (ash z 20)))
101 (define-inlinable (pack-u8-u8-u16 x y z)
103 (error "out of range" x))
105 (error "out of range" y))
106 (logior x (ash y 8) (ash z 16)))
108 (define-inlinable (pack-u8-u8-u8-u8 x y z w)
110 (error "out of range" x))
112 (error "out of range" y))
114 (error "out of range" z))
115 (logior x (ash y 8) (ash z 16) (ash w 24)))
117 (define-syntax pack-flags
119 ;; Add clauses as needed.
120 ((pack-flags f1 f2) (logior (if f1 (ash 1 0) 0)
121 (if f2 (ash 2 0) 0)))))
123 ;;; Helpers to read and write 32-bit units in a buffer.
125 (define-syntax-rule (u32-ref buf n)
126 (bytevector-u32-native-ref buf (* n 4)))
128 (define-syntax-rule (u32-set! buf n val)
129 (bytevector-u32-native-set! buf (* n 4) val))
131 (define-syntax-rule (s32-ref buf n)
132 (bytevector-s32-native-ref buf (* n 4)))
134 (define-syntax-rule (s32-set! buf n val)
135 (bytevector-s32-native-set! buf (* n 4) val))
140 ;;; A <meta> entry collects metadata for one procedure. Procedures are
141 ;;; written as contiguous ranges of RTL code.
143 (define-syntax-rule (assert-match arg pattern kind)
145 (unless (match x (pattern #t) (_ #f))
146 (error (string-append "expected " kind) x))))
148 (define-record-type <meta>
149 (%make-meta label properties low-pc high-pc arities)
152 (properties meta-properties set-meta-properties!)
154 (high-pc meta-high-pc set-meta-high-pc!)
155 (arities meta-arities set-meta-arities!))
157 (define (make-meta label properties low-pc)
158 (assert-match label (? symbol?) "symbol")
159 (assert-match properties (((? symbol?) . _) ...) "alist with symbolic keys")
160 (%make-meta label properties low-pc #f '()))
162 (define (meta-name meta)
163 (assq-ref (meta-properties meta) 'name))
165 ;; Metadata for one <lambda-case>.
166 (define-record-type <arity>
167 (make-arity req opt rest kw-indices allow-other-keys?
173 (kw-indices arity-kw-indices)
174 (allow-other-keys? arity-allow-other-keys?)
175 (low-pc arity-low-pc)
176 (high-pc arity-high-pc set-arity-high-pc!))
178 (define-syntax *block-size* (identifier-syntax 32))
180 ;;; An assembler collects all of the words emitted during assembly, and
181 ;;; also maintains ancillary information such as the constant table, a
182 ;;; relocation list, and so on.
184 ;;; RTL code consists of 32-bit units. We emit RTL code using native
185 ;;; endianness. If we're targeting a foreign endianness, we byte-swap
186 ;;; the bytevector as a whole instead of conditionalizing each access.
188 (define-record-type <asm>
189 (make-asm cur idx start prev written
193 shstrtab next-section-number
197 ;; We write RTL code into what is logically a growable vector,
198 ;; implemented as a list of blocks. asm-cur is the current block, and
199 ;; asm-idx is the current index into that block, in 32-bit units.
201 (cur asm-cur set-asm-cur!)
202 (idx asm-idx set-asm-idx!)
204 ;; asm-start is an absolute position, indicating the offset of the
205 ;; beginning of an instruction (in u32 units). It is updated after
206 ;; writing all the words for one primitive instruction. It models the
207 ;; position of the instruction pointer during execution, given that
208 ;; the RTL VM updates the IP only at the end of executing the
209 ;; instruction, and is thus useful for computing offsets between two
210 ;; points in a program.
212 (start asm-start set-asm-start!)
214 ;; The list of previously written blocks.
216 (prev asm-prev set-asm-prev!)
218 ;; The number of u32 words written in asm-prev, which is the same as
219 ;; the offset of the current block.
221 (written asm-written set-asm-written!)
223 ;; An alist of symbol -> position pairs, indicating the labels defined
224 ;; in this compilation unit.
226 (labels asm-labels set-asm-labels!)
228 ;; A list of relocations needed by the program text. We use an
229 ;; internal representation for relocations, and handle textualn
230 ;; relative relocations in the assembler. Other kinds of relocations
231 ;; are later reified as linker relocations and resolved by the linker.
233 (relocs asm-relocs set-asm-relocs!)
235 ;; Target information.
237 (word-size asm-word-size)
238 (endianness asm-endianness)
240 ;; The constant table, as a vhash of object -> label. All constants
241 ;; get de-duplicated and written into separate sections -- either the
242 ;; .rodata section, for read-only data, or .data, for constants that
243 ;; need initialization at load-time (like symbols). Constants can
244 ;; depend on other constants (e.g. a symbol depending on a stringbuf),
245 ;; so order in this table is important.
247 (constants asm-constants set-asm-constants!)
249 ;; A list of RTL instructions needed to initialize the constants.
250 ;; Will run in a thunk with 2 local variables.
252 (inits asm-inits set-asm-inits!)
254 ;; The shstrtab, for section names.
256 (shstrtab asm-shstrtab set-asm-shstrtab!)
258 ;; The section number for the next section to be written.
260 (next-section-number asm-next-section-number set-asm-next-section-number!)
262 ;; A list of <meta>, corresponding to procedure metadata.
264 (meta asm-meta set-asm-meta!)
266 ;; A list of (pos . source) pairs, indicating source information. POS
267 ;; is relative to the beginning of the text section, and SOURCE is in
268 ;; the same format that source-properties returns.
270 (sources asm-sources set-asm-sources!))
272 (define-inlinable (fresh-block)
273 (make-u32vector *block-size*))
275 (define* (make-assembler #:key (word-size (target-word-size))
276 (endianness (target-endianness)))
277 "Create an assembler for a given target @var{word-size} and
278 @var{endianness}, falling back to appropriate values for the configured
280 (make-asm (fresh-block) 0 0 '() 0
284 (make-string-table) 1
287 (define (intern-section-name! asm string)
288 "Add a string to the section name table (shstrtab)."
289 (string-table-intern! (asm-shstrtab asm) string))
291 (define-inlinable (asm-pos asm)
292 "The offset of the next word to be written into the code buffer, in
294 (+ (asm-idx asm) (asm-written asm)))
296 (define (allocate-new-block asm)
297 "Close off the current block, and arrange for the next word to be
298 written to a fresh block."
299 (let ((new (fresh-block)))
300 (set-asm-prev! asm (cons (asm-cur asm) (asm-prev asm)))
301 (set-asm-written! asm (asm-pos asm))
302 (set-asm-cur! asm new)
303 (set-asm-idx! asm 0)))
305 (define-inlinable (emit asm u32)
306 "Emit one 32-bit word into the instruction stream. Assumes that there
307 is space for the word, and ensures that there is space for the next
309 (u32-set! (asm-cur asm) (asm-idx asm) u32)
310 (set-asm-idx! asm (1+ (asm-idx asm)))
311 (if (= (asm-idx asm) *block-size*)
312 (allocate-new-block asm)))
314 (define-inlinable (make-reloc type label base word)
315 "Make an internal relocation of type @var{type} referencing symbol
316 @var{label}, @var{word} words after position @var{start}. @var{type}
317 may be x8-s24, indicating a 24-bit relative label reference that can be
318 fixed up by the assembler, or s32, indicating a 32-bit relative
319 reference that needs to be fixed up by the linker."
320 (list type label base word))
322 (define-inlinable (reset-asm-start! asm)
323 "Reset the asm-start after writing the words for one instruction."
324 (set-asm-start! asm (asm-pos asm)))
326 (define (emit-exported-label asm label)
327 "Define a linker symbol associating @var{label} with the current
329 (set-asm-labels! asm (acons label (asm-start asm) (asm-labels asm))))
331 (define (record-label-reference asm label)
332 "Record an x8-s24 local label reference. This value will get patched
333 up later by the assembler."
334 (let* ((start (asm-start asm))
336 (reloc (make-reloc 'x8-s24 label start (- pos start))))
337 (set-asm-relocs! asm (cons reloc (asm-relocs asm)))))
339 (define* (record-far-label-reference asm label #:optional (offset 0))
340 "Record an s32 far label reference. This value will get patched up
341 later by the linker."
342 (let* ((start (- (asm-start asm) offset))
344 (reloc (make-reloc 's32 label start (- pos start))))
345 (set-asm-relocs! asm (cons reloc (asm-relocs asm)))))
351 ;;; Primitive assemblers are defined by expanding `assembler' for each
352 ;;; opcode in `(rtl-instruction-list)'.
355 (eval-when (expand compile load eval)
356 (define (id-append ctx a b)
357 (datum->syntax ctx (symbol-append (syntax->datum a) (syntax->datum b)))))
359 (define-syntax assembler
361 (define-syntax op-case
364 ((_ asm name ((type arg ...) code ...) clause ...)
365 #`(if (eq? name 'type)
366 (with-syntax (((arg ...) (generate-temporaries #'(arg ...))))
369 (op-case asm name clause ...)))
371 #'(error "unmatched name" name)))))
373 (define (pack-first-word asm opcode type)
374 (with-syntax ((opcode opcode))
380 (emit asm (pack-u8-u24 opcode arg)))
382 (record-label-reference asm label)
385 (emit asm (pack-u8-u8-u16 opcode a (object-address imm))))
387 (emit asm (pack-u8-u12-u12 opcode a b)))
389 (emit asm (pack-u8-u8-u8-u8 opcode a b c))))))
391 (define (pack-tail-word asm type)
395 (emit asm (pack-u8-u24 a b)))
397 (record-label-reference asm label)
400 (emit asm (pack-u8-u8-u16 a b (object-address imm))))
402 (emit asm (pack-u8-u12-u12 a b c)))
403 ((U8_U8_U8_U8 a b c d)
404 (emit asm (pack-u8-u8-u8-u8 a b c d)))
408 (let ((val (object-address imm)))
409 (unless (zero? (ash val -32))
410 (error "FIXME: enable truncation of negative fixnums when cross-compiling"))
413 (unless (= (asm-word-size asm) 8)
414 (error "make-long-immediate unavailable for this target"))
415 (emit asm (ash (object-address imm) -32))
416 (emit asm (logand (object-address imm) (1- (ash 1 32)))))
419 (record-far-label-reference asm label)
422 (record-far-label-reference asm label)
425 (record-far-label-reference asm label)
428 (record-far-label-reference asm label
429 (* offset (/ (asm-word-size asm) 4)))
432 (emit asm (pack-u8-u24 0 a)))
434 (emit asm (pack-u8-u12-u12 0 a b)))
436 (record-label-reference asm label)
439 (record-label-reference asm label)
440 (emit asm (pack-u1-u7-u24 (if a 1 0) 0 0)))
441 ((B1_U7_L24 a b label)
442 (record-label-reference asm label)
443 (emit asm (pack-u1-u7-u24 (if a 1 0) b 0)))
445 (emit asm (pack-u1-u7-u24 (if a 1 0) 0 0)))
447 (emit asm (pack-u1-u7-u24 (if a 1 0) 0 b)))))
450 ((_ name opcode word0 word* ...)
451 (with-syntax ((((formal0 ...)
453 (pack-first-word #'asm
454 (syntax->datum #'opcode)
455 (syntax->datum #'word0)))
458 (map (lambda (word) (pack-tail-word #'asm word))
459 (syntax->datum #'(word* ...)))))
460 #'(lambda (asm formal0 ... formal* ... ...)
461 (unless (asm? asm) (error "not an asm"))
464 (reset-asm-start! asm)))))))
466 (define assemblers (make-hash-table))
468 (define-syntax define-assembler
471 ((_ name opcode kind arg ...)
472 (with-syntax ((emit (id-append #'name #'emit- #'name)))
475 (let ((emit (assembler name opcode arg ...)))
476 (hashq-set! assemblers 'name emit)
480 (define-syntax visit-opcodes
483 ((visit-opcodes macro arg ...)
484 (with-syntax (((inst ...)
485 (map (lambda (x) (datum->syntax #'macro x))
486 (rtl-instruction-list))))
488 (macro arg ... . inst)
491 (visit-opcodes define-assembler)
493 (define (emit-text asm instructions)
494 "Assemble @var{instructions} using the assembler @var{asm}.
495 @var{instructions} is a sequence of RTL instructions, expressed as a
496 list of lists. This procedure can be called many times before calling
497 @code{link-assembly}."
498 (for-each (lambda (inst)
499 (apply (or (hashq-ref assemblers (car inst))
500 (error 'bad-instruction inst))
508 ;;; The constant table records a topologically sorted set of literal
509 ;;; constants used by a program. For example, a pair uses its car and
510 ;;; cdr, a string uses its stringbuf, etc.
512 ;;; Some things we want to add to the constant table are not actually
513 ;;; Scheme objects: for example, stringbufs, cache cells for toplevel
514 ;;; references, or cache cells for non-closure procedures. For these we
515 ;;; define special record types and add instances of those record types
519 (define-inlinable (immediate? x)
520 "Return @code{#t} if @var{x} is immediate, and @code{#f} otherwise."
521 (not (zero? (logand (object-address x) 6))))
523 (define-record-type <stringbuf>
524 (make-stringbuf string)
526 (string stringbuf-string))
528 (define-record-type <static-procedure>
529 (make-static-procedure code)
531 (code static-procedure-code))
533 (define-record-type <uniform-vector-backing-store>
534 (make-uniform-vector-backing-store bytes)
535 uniform-vector-backing-store?
536 (bytes uniform-vector-backing-store-bytes))
538 (define-record-type <cache-cell>
539 (make-cache-cell scope key)
541 (scope cache-cell-scope)
542 (key cache-cell-key))
544 (define (simple-vector? obj)
546 (equal? (array-shape obj) (list (list 0 (1- (vector-length obj)))))))
548 (define (simple-uniform-vector? obj)
550 (symbol? (array-type obj))
551 (equal? (array-shape obj) (list (list 0 (1- (array-length obj)))))))
553 (define (statically-allocatable? x)
554 "Return @code{#t} if a non-immediate constant can be allocated
555 statically, and @code{#f} if it would need some kind of runtime
557 (or (pair? x) (string? x) (stringbuf? x) (static-procedure? x) (array? x)))
559 (define (intern-constant asm obj)
560 "Add an object to the constant table, and return a label that can be
561 used to reference it. If the object is already present in the constant
562 table, its existing label is used directly."
564 (intern-constant asm obj))
565 (define (field dst n obj)
566 (let ((src (recur obj)))
568 (if (statically-allocatable? obj)
569 `((static-patch! ,dst ,n ,src))
570 `((static-ref 1 ,src)
571 (static-set! 1 ,dst ,n)))
573 (define (intern obj label)
576 (append (field label 0 (car obj))
577 (field label 1 (cdr obj))))
578 ((simple-vector? obj)
579 (let lp ((i 0) (inits '()))
580 (if (< i (vector-length obj))
582 (append-reverse (field label (1+ i) (vector-ref obj i))
585 ((stringbuf? obj) '())
586 ((static-procedure? obj)
587 `((static-patch! ,label 1 ,(static-procedure-code obj))))
588 ((cache-cell? obj) '())
590 `((make-non-immediate 1 ,(recur (symbol->string obj)))
592 (static-set! 1 ,label 0)))
594 `((static-patch! ,label 1 ,(recur (make-stringbuf obj)))))
596 `((static-ref 1 ,(recur (keyword->symbol obj)))
597 (symbol->keyword 1 1)
598 (static-set! 1 ,label 0)))
600 `((make-non-immediate 1 ,(recur (number->string obj)))
602 (static-set! 1 ,label 0)))
603 ((uniform-vector-backing-store? obj) '())
604 ((simple-uniform-vector? obj)
605 `((static-patch! ,label 2
606 ,(recur (make-uniform-vector-backing-store obj)))))
608 (error "don't know how to intern" obj))))
610 ((immediate? obj) #f)
611 ((vhash-assoc obj (asm-constants asm)) => cdr)
613 ;; Note that calling intern may mutate asm-constants and
614 ;; asm-constant-inits.
615 (let* ((label (gensym "constant"))
616 (inits (intern obj label)))
617 (set-asm-constants! asm (vhash-cons obj label (asm-constants asm)))
618 (set-asm-inits! asm (append-reverse inits (asm-inits asm)))
621 (define (intern-non-immediate asm obj)
622 "Intern a non-immediate into the constant table, and return its
624 (when (immediate? obj)
625 (error "expected a non-immediate" obj))
626 (intern-constant asm obj))
628 (define (intern-cache-cell asm scope key)
629 "Intern a cache cell into the constant table, and return its label.
630 If there is already a cache cell with the given scope and key, it is
632 (intern-constant asm (make-cache-cell scope key)))
634 ;; Return the label of the cell that holds the module for a scope.
635 (define (intern-module-cache-cell asm scope)
636 "Intern a cache cell for a module, and return its label."
637 (intern-cache-cell asm scope #t))
643 ;;; Macro assemblers bridge the gap between primitive instructions and
644 ;;; some higher-level operations.
647 (define-syntax define-macro-assembler
650 ((_ (name arg ...) body body* ...)
651 (with-syntax ((emit (id-append #'name #'emit- #'name)))
654 (let ((emit (lambda (arg ...) body body* ...)))
655 (hashq-set! assemblers 'name emit)
659 (define-macro-assembler (load-constant asm dst obj)
662 (let ((bits (object-address obj)))
664 ((and (< dst 256) (zero? (ash bits -16)))
665 (emit-make-short-immediate asm dst obj))
666 ((zero? (ash bits -32))
667 (emit-make-long-immediate asm dst obj))
669 (emit-make-long-long-immediate asm dst obj)))))
670 ((statically-allocatable? obj)
671 (emit-make-non-immediate asm dst (intern-non-immediate asm obj)))
673 (emit-static-ref asm dst (intern-non-immediate asm obj)))))
675 (define-macro-assembler (load-static-procedure asm dst label)
676 (let ((loc (intern-constant asm (make-static-procedure label))))
677 (emit-make-non-immediate asm dst loc)))
679 (define-syntax-rule (define-tc7-macro-assembler name tc7)
680 (define-macro-assembler (name asm slot invert? label)
681 (emit-br-if-tc7 asm slot invert? tc7 label)))
683 ;; Keep in sync with tags.h. Part of Guile's ABI. Currently unused
684 ;; macro assemblers are commented out. See also
685 ;; *branching-primcall-arities* in (language cps primitives), the set of
686 ;; macro-instructions in assembly.scm, and
687 ;; disassembler.scm:code-annotation.
689 ;; FIXME: Define all tc7 values in Scheme in one place, derived from
691 (define-tc7-macro-assembler br-if-symbol 5)
692 (define-tc7-macro-assembler br-if-variable 7)
693 (define-tc7-macro-assembler br-if-vector 13)
694 ;(define-tc7-macro-assembler br-if-weak-vector 13)
695 (define-tc7-macro-assembler br-if-string 21)
696 ;(define-tc7-macro-assembler br-if-heap-number 23)
697 ;(define-tc7-macro-assembler br-if-stringbuf 39)
698 (define-tc7-macro-assembler br-if-bytevector 77)
699 ;(define-tc7-macro-assembler br-if-pointer 31)
700 ;(define-tc7-macro-assembler br-if-hashtable 29)
701 ;(define-tc7-macro-assembler br-if-fluid 37)
702 ;(define-tc7-macro-assembler br-if-dynamic-state 45)
703 ;(define-tc7-macro-assembler br-if-frame 47)
704 ;(define-tc7-macro-assembler br-if-objcode 53)
705 ;(define-tc7-macro-assembler br-if-vm 55)
706 ;(define-tc7-macro-assembler br-if-vm-cont 71)
707 ;(define-tc7-macro-assembler br-if-rtl-program 69)
708 ;(define-tc7-macro-assembler br-if-program 79)
709 ;(define-tc7-macro-assembler br-if-weak-set 85)
710 ;(define-tc7-macro-assembler br-if-weak-table 87)
711 ;(define-tc7-macro-assembler br-if-array 93)
712 ;(define-tc7-macro-assembler br-if-bitvector 95)
713 ;(define-tc7-macro-assembler br-if-port 125)
714 ;(define-tc7-macro-assembler br-if-smob 127)
716 (define-macro-assembler (begin-program asm label properties)
717 (emit-label asm label)
718 (let ((meta (make-meta label properties (asm-start asm))))
719 (set-asm-meta! asm (cons meta (asm-meta asm)))))
721 (define-macro-assembler (end-program asm)
722 (let ((meta (car (asm-meta asm))))
723 (set-meta-high-pc! meta (asm-start asm))
724 (set-meta-arities! meta (reverse (meta-arities meta)))))
726 (define-macro-assembler (begin-standard-arity asm req nlocals alternate)
727 (emit-begin-opt-arity asm req '() #f nlocals alternate))
729 (define-macro-assembler (begin-opt-arity asm req opt rest nlocals alternate)
730 (emit-begin-kw-arity asm req opt rest '() #f nlocals alternate))
732 (define-macro-assembler (begin-kw-arity asm req opt rest kw-indices
733 allow-other-keys? nlocals alternate)
734 (assert-match req ((? symbol?) ...) "list of symbols")
735 (assert-match opt ((? symbol?) ...) "list of symbols")
736 (assert-match rest (or #f (? symbol?)) "#f or symbol")
737 (assert-match kw-indices (((? keyword?) . (? integer?)) ...)
738 "alist of keyword -> integer")
739 (assert-match allow-other-keys? (? boolean?) "boolean")
740 (assert-match nlocals (? integer?) "integer")
741 (assert-match alternate (or #f (? symbol?)) "#f or symbol")
742 (let* ((meta (car (asm-meta asm)))
743 (arity (make-arity req opt rest kw-indices allow-other-keys?
745 ;; The procedure itself is in slot 0, in the standard calling
746 ;; convention. For procedure prologues, nreq includes the
747 ;; procedure, so here we add 1.
748 (nreq (1+ (length req)))
750 (rest? (->bool rest)))
751 (set-meta-arities! meta (cons arity (meta-arities meta)))
753 ((or allow-other-keys? (pair? kw-indices))
754 (emit-kw-prelude asm nreq nopt rest? kw-indices allow-other-keys?
756 ((or rest? (pair? opt))
757 (emit-opt-prelude asm nreq nopt rest? nlocals alternate))
759 (emit-standard-prelude asm nreq nlocals alternate)))))
761 (define-macro-assembler (end-arity asm)
762 (let ((arity (car (meta-arities (car (asm-meta asm))))))
763 (set-arity-high-pc! arity (asm-start asm))))
765 (define-macro-assembler (standard-prelude asm nreq nlocals alternate)
768 (emit-br-if-nargs-ne asm nreq alternate)
769 (emit-alloc-frame asm nlocals))
770 ((and (< nreq (ash 1 12)) (< (- nlocals nreq) (ash 1 12)))
771 (emit-assert-nargs-ee/locals asm nreq (- nlocals nreq)))
773 (emit-assert-nargs-ee asm nreq)
774 (emit-alloc-frame asm nlocals))))
776 (define-macro-assembler (opt-prelude asm nreq nopt rest? nlocals alternate)
778 (emit-br-if-nargs-lt asm nreq alternate)
779 (emit-assert-nargs-ge asm nreq))
782 (emit-bind-rest asm (+ nreq nopt)))
784 (emit-br-if-nargs-gt asm (+ nreq nopt) alternate))
786 (emit-assert-nargs-le asm (+ nreq nopt))))
787 (emit-alloc-frame asm nlocals))
789 (define-macro-assembler (kw-prelude asm nreq nopt rest? kw-indices
790 allow-other-keys? nlocals alternate)
792 (emit-br-if-nargs-lt asm nreq alternate)
793 (emit-assert-nargs-ge asm nreq))
794 (let ((ntotal (fold (lambda (kw ntotal)
796 (((? keyword?) . idx)
797 (max (1+ idx) ntotal))))
798 (+ nreq nopt) kw-indices)))
799 ;; FIXME: port 581f410f
800 (emit-bind-kwargs asm nreq
801 (pack-flags allow-other-keys? rest?)
804 (intern-constant asm kw-indices))
805 (emit-alloc-frame asm nlocals)))
807 (define-macro-assembler (label asm sym)
808 (set-asm-labels! asm (acons sym (asm-start asm) (asm-labels asm))))
810 (define-macro-assembler (source asm source)
811 (set-asm-sources! asm (acons (asm-start asm) source (asm-sources asm))))
813 (define-macro-assembler (cache-current-module! asm module scope)
814 (let ((mod-label (intern-module-cache-cell asm scope)))
815 (emit-static-set! asm module mod-label 0)))
817 (define-macro-assembler (cached-toplevel-box asm dst scope sym bound?)
818 (let ((sym-label (intern-non-immediate asm sym))
819 (mod-label (intern-module-cache-cell asm scope))
820 (cell-label (intern-cache-cell asm scope sym)))
821 (emit-toplevel-box asm dst cell-label mod-label sym-label bound?)))
823 (define-macro-assembler (cached-module-box asm dst module-name sym public? bound?)
824 (let* ((sym-label (intern-non-immediate asm sym))
825 (key (cons public? module-name))
826 (mod-name-label (intern-constant asm key))
827 (cell-label (intern-cache-cell asm key sym)))
828 (emit-module-box asm dst cell-label mod-name-label sym-label bound?)))
834 ;;; Helper for linking objects.
837 (define (make-object asm name bv relocs labels . kwargs)
838 "Make a linker object. This helper handles interning the name in the
839 shstrtab, assigning the size, allocating a fresh index, and defining a
840 corresponding linker symbol for the start of the section."
841 (let ((name-idx (intern-section-name! asm (symbol->string name)))
842 (index (asm-next-section-number asm)))
843 (set-asm-next-section-number! asm (1+ index))
844 (make-linker-object (apply make-elf-section
847 #:size (bytevector-length bv)
850 (cons (make-linker-symbol name 0) labels))))
856 ;;; Linking the constant table. This code is somewhat intertwingled
857 ;;; with the intern-constant code above, as that procedure also
858 ;;; residualizes instructions to initialize constants at load time.
861 (define (write-immediate asm buf pos x)
862 (let ((val (object-address x))
863 (endianness (asm-endianness asm)))
864 (case (asm-word-size asm)
865 ((4) (bytevector-u32-set! buf pos val endianness))
866 ((8) (bytevector-u64-set! buf pos val endianness))
867 (else (error "bad word size" asm)))))
869 (define (emit-init-constants asm)
870 "If there is writable data that needs initialization at runtime, emit
871 a procedure to do that and return its label. Otherwise return
873 (let ((inits (asm-inits asm)))
874 (and (not (null? inits))
875 (let ((label (gensym "init-constants")))
877 `((begin-program ,label ())
878 (assert-nargs-ee/locals 1 1)
880 (load-constant 1 ,*unspecified*)
885 (define (link-data asm data name)
886 "Link the static data for a program into the @var{name} section (which
887 should be .data or .rodata), and return the resulting linker object.
888 @var{data} should be a vhash mapping objects to labels."
889 (define (align address alignment)
891 (modulo (- alignment (modulo address alignment)) alignment)))
893 (define tc7-vector 13)
894 (define stringbuf-shared-flag #x100)
895 (define stringbuf-wide-flag #x400)
896 (define tc7-stringbuf 39)
897 (define tc7-narrow-stringbuf
898 (+ tc7-stringbuf stringbuf-shared-flag))
899 (define tc7-wide-stringbuf
900 (+ tc7-stringbuf stringbuf-shared-flag stringbuf-wide-flag))
901 (define tc7-ro-string (+ 21 #x200))
902 (define tc7-rtl-program 69)
903 (define tc7-bytevector 77)
905 (let ((word-size (asm-word-size asm))
906 (endianness (asm-endianness asm)))
907 (define (byte-length x)
910 (let ((x (stringbuf-string x)))
912 (case (string-bytes-per-char x)
913 ((1) (1+ (string-length x)))
914 ((4) (* (1+ (string-length x)) 4))
915 (else (error "bad string bytes per char" x))))))
916 ((static-procedure? x)
923 (* (1+ (vector-length x)) word-size))
924 ((simple-uniform-vector? x)
926 ((uniform-vector-backing-store? x)
927 (bytevector-length (uniform-vector-backing-store-bytes x)))
931 (define (write-constant-reference buf pos x)
932 ;; The asm-inits will fix up any reference to a non-immediate.
933 (write-immediate asm buf pos (if (immediate? x) x #f)))
935 (define (write buf pos obj)
938 (let* ((x (stringbuf-string obj))
939 (len (string-length x))
940 (tag (if (= (string-bytes-per-char x) 1)
942 tc7-wide-stringbuf)))
945 (bytevector-u32-set! buf pos tag endianness)
946 (bytevector-u32-set! buf (+ pos 4) len endianness))
948 (bytevector-u64-set! buf pos tag endianness)
949 (bytevector-u64-set! buf (+ pos 8) len endianness))
951 (error "bad word size" asm)))
952 (let ((pos (+ pos (* word-size 2))))
953 (case (string-bytes-per-char x)
957 (let ((u8 (char->integer (string-ref x i))))
958 (bytevector-u8-set! buf (+ pos i) u8)
960 (bytevector-u8-set! buf (+ pos i) 0))))
964 (let ((u32 (char->integer (string-ref x i))))
965 (bytevector-u32-set! buf (+ pos (* i 4)) u32 endianness)
967 (bytevector-u32-set! buf (+ pos (* i 4)) 0 endianness))))
968 (else (error "bad string bytes per char" x))))))
970 ((static-procedure? obj)
973 (bytevector-u32-set! buf pos tc7-rtl-program endianness)
974 (bytevector-u32-set! buf (+ pos 4) 0 endianness))
976 (bytevector-u64-set! buf pos tc7-rtl-program endianness)
977 (bytevector-u64-set! buf (+ pos 8) 0 endianness))
978 (else (error "bad word size"))))
981 (write-immediate asm buf pos #f))
984 (let ((tag (logior tc7-ro-string (ash (string-length obj) 8))))
987 (bytevector-u32-set! buf pos tc7-ro-string endianness)
988 (write-immediate asm buf (+ pos 4) #f) ; stringbuf
989 (bytevector-u32-set! buf (+ pos 8) 0 endianness)
990 (bytevector-u32-set! buf (+ pos 12) (string-length obj) endianness))
992 (bytevector-u64-set! buf pos tc7-ro-string endianness)
993 (write-immediate asm buf (+ pos 8) #f) ; stringbuf
994 (bytevector-u64-set! buf (+ pos 16) 0 endianness)
995 (bytevector-u64-set! buf (+ pos 24) (string-length obj) endianness))
996 (else (error "bad word size")))))
999 (write-constant-reference buf pos (car obj))
1000 (write-constant-reference buf (+ pos word-size) (cdr obj)))
1002 ((simple-vector? obj)
1003 (let* ((len (vector-length obj))
1004 (tag (logior tc7-vector (ash len 8))))
1006 ((4) (bytevector-u32-set! buf pos tag endianness))
1007 ((8) (bytevector-u64-set! buf pos tag endianness))
1008 (else (error "bad word size")))
1010 (when (< i (vector-length obj))
1011 (let ((pos (+ pos word-size (* i word-size)))
1012 (elt (vector-ref obj i)))
1013 (write-constant-reference buf pos elt)
1017 (write-immediate asm buf pos #f))
1020 (write-immediate asm buf pos #f))
1023 (write-immediate asm buf pos #f))
1025 ((simple-uniform-vector? obj)
1026 (let ((tag (logior tc7-bytevector
1027 (ash (uniform-vector-element-type-code obj) 7))))
1030 (bytevector-u32-set! buf pos tag endianness)
1031 (bytevector-u32-set! buf (+ pos 4) (bytevector-length obj)
1032 endianness) ; length
1033 (bytevector-u32-set! buf (+ pos 8) 0 endianness) ; pointer
1034 (write-immediate asm buf (+ pos 12) #f)) ; owner
1036 (bytevector-u64-set! buf pos tag endianness)
1037 (bytevector-u64-set! buf (+ pos 8) (bytevector-length obj)
1038 endianness) ; length
1039 (bytevector-u64-set! buf (+ pos 16) 0 endianness) ; pointer
1040 (write-immediate asm buf (+ pos 24) #f)) ; owner
1041 (else (error "bad word size")))))
1043 ((uniform-vector-backing-store? obj)
1044 (let ((bv (uniform-vector-backing-store-bytes obj)))
1045 (bytevector-copy! bv 0 buf pos (bytevector-length bv))
1046 (unless (or (= 1 (uniform-vector-element-size bv))
1047 (eq? endianness (native-endianness)))
1048 ;; Need to swap units of element-size bytes
1049 (error "FIXME: Implement byte order swap"))))
1052 (error "unrecognized object" obj))))
1055 ((vlist-null? data) #f)
1057 (let* ((byte-len (vhash-fold (lambda (k v len)
1058 (+ (byte-length k) (align len 8)))
1060 (buf (make-bytevector byte-len 0)))
1061 (let lp ((i 0) (pos 0) (labels '()))
1062 (if (< i (vlist-length data))
1063 (let* ((pair (vlist-ref data i))
1065 (obj-label (cdr pair)))
1068 (align (+ (byte-length obj) pos) 8)
1069 (cons (make-linker-symbol obj-label pos) labels)))
1070 (make-object asm name buf '() labels
1072 ('.data (logior SHF_ALLOC SHF_WRITE))
1073 ('.rodata SHF_ALLOC))))))))))
1075 (define (link-constants asm)
1076 "Link sections to hold constants needed by the program text emitted
1079 Returns three values: an object for the .rodata section, an object for
1080 the .data section, and a label for an initialization procedure. Any of
1081 these may be @code{#f}."
1082 (define (shareable? x)
1086 (and (immediate? (car x)) (immediate? (cdr x))))
1089 (or (= i (vector-length x))
1090 (and (immediate? (vector-ref x i))
1092 ((uniform-vector-backing-store? x) #t)
1094 (let* ((constants (asm-constants asm))
1095 (len (vlist-length constants)))
1100 (values (link-data asm ro '.rodata)
1101 (link-data asm rw '.data)
1102 (emit-init-constants asm))
1103 (let ((pair (vlist-ref constants i)))
1104 (if (shareable? (car pair))
1105 (lp (1+ i) (vhash-consq (car pair) (cdr pair) ro) rw)
1106 (lp (1+ i) ro (vhash-consq (car pair) (cdr pair) rw))))))))
1111 ;;; Linking program text.
1114 (define (process-relocs buf relocs labels)
1115 "Patch up internal x8-s24 relocations, and any s32 relocations that
1116 reference symbols in the text section. Return a list of linker
1117 relocations for references to symbols defined outside the text section."
1119 (lambda (reloc tail)
1121 ((type label base word)
1122 (let ((abs (assq-ref labels label))
1123 (dst (+ base word)))
1127 (let ((rel (- abs base)))
1128 (s32-set! buf dst rel)
1130 (cons (make-linker-reloc 'rel32/4 (* dst 4) word label)
1134 (error "unbound near relocation" reloc))
1135 (let ((rel (- abs base))
1136 (u32 (u32-ref buf dst)))
1137 (u32-set! buf dst (pack-u8-s24 (logand u32 #xff) rel))
1139 (else (error "bad relocation kind" reloc)))))))
1143 (define (process-labels labels)
1144 "Define linker symbols for the label-offset pairs in @var{labels}.
1145 The offsets are expected to be expressed in words."
1147 (make-linker-symbol (car pair) (* (cdr pair) 4)))
1150 (define (swap-bytes! buf)
1151 "Patch up the text buffer @var{buf}, swapping the endianness of each
1153 (unless (zero? (modulo (bytevector-length buf) 4))
1154 (error "unexpected length"))
1155 (let ((byte-len (bytevector-length buf)))
1157 (unless (= pos byte-len)
1158 (bytevector-u32-set!
1160 (bytevector-u32-ref buf pos (endianness big))
1161 (endianness little))
1164 (define (link-text-object asm)
1165 "Link the .rtl-text section, swapping the endianness of the bytes if
1167 (let ((buf (make-u32vector (asm-pos asm))))
1168 (let lp ((pos 0) (prev (reverse (asm-prev asm))))
1170 (let ((byte-size (* (asm-idx asm) 4)))
1171 (bytevector-copy! (asm-cur asm) 0 buf pos byte-size)
1172 (unless (eq? (asm-endianness asm) (native-endianness))
1174 (make-object asm '.rtl-text
1176 (process-relocs buf (asm-relocs asm)
1178 (process-labels (asm-labels asm))))
1179 (let ((len (* *block-size* 4)))
1180 (bytevector-copy! (car prev) 0 buf pos len)
1181 (lp (+ pos len) (cdr prev)))))))
1187 ;;; Linking other sections of the ELF file, like the dynamic segment,
1188 ;;; the symbol table, etc.
1191 (define (link-dynamic-section asm text rw rw-init)
1192 "Link the dynamic section for an ELF image with RTL text, given the
1193 writable data section @var{rw} needing fixup from the procedure with
1194 label @var{rw-init}. @var{rw-init} may be false. If @var{rw} is true,
1195 it will be added to the GC roots at runtime."
1196 (define-syntax-rule (emit-dynamic-section word-size %set-uword! reloc-type)
1197 (let* ((endianness (asm-endianness asm))
1198 (bv (make-bytevector (* word-size (if rw (if rw-init 12 10) 6)) 0))
1201 (%set-uword! bv (* i word-size) uword endianness)))
1205 (set! relocs (cons (make-linker-reloc 'reloc-type
1206 (* i word-size) 0 label)
1208 (%set-uword! bv (* i word-size) 0 endianness))))
1209 (set-uword! 0 DT_GUILE_RTL_VERSION)
1210 (set-uword! 1 #x02020000)
1211 (set-uword! 2 DT_GUILE_ENTRY)
1212 (set-label! 3 '.rtl-text)
1216 (set-uword! 4 DT_GUILE_GC_ROOT)
1217 (set-label! 5 '.data)
1218 (set-uword! 6 DT_GUILE_GC_ROOT_SZ)
1219 (set-uword! 7 (bytevector-length (linker-object-bv rw)))
1222 (set-uword! 8 DT_INIT) ; constants
1223 (set-label! 9 rw-init)
1224 (set-uword! 10 DT_NULL)
1227 (set-uword! 8 DT_NULL)
1230 (set-uword! 4 DT_NULL)
1232 (make-object asm '.dynamic bv relocs '()
1233 #:type SHT_DYNAMIC #:flags SHF_ALLOC)))
1234 (case (asm-word-size asm)
1235 ((4) (emit-dynamic-section 4 bytevector-u32-set! abs32/1))
1236 ((8) (emit-dynamic-section 8 bytevector-u64-set! abs64/1))
1237 (else (error "bad word size" asm))))
1239 (define (link-shstrtab asm)
1240 "Link the string table for the section headers."
1241 (intern-section-name! asm ".shstrtab")
1242 (make-object asm '.shstrtab
1243 (link-string-table! (asm-shstrtab asm))
1245 #:type SHT_STRTAB #:flags 0))
1247 (define (link-symtab text-section asm)
1248 (let* ((endianness (asm-endianness asm))
1249 (word-size (asm-word-size asm))
1250 (size (elf-symbol-len word-size))
1251 (meta (reverse (asm-meta asm)))
1253 (strtab (make-string-table))
1254 (bv (make-bytevector (* n size) 0)))
1255 (define (intern-string! name)
1256 (string-table-intern! strtab (if name (symbol->string name) "")))
1259 (let ((name (intern-string! (meta-name meta))))
1260 (write-elf-symbol bv (* n size) endianness word-size
1263 ;; Symbol value and size are measured in
1265 #:value (* 4 (meta-low-pc meta))
1266 #:size (* 4 (- (meta-high-pc meta)
1267 (meta-low-pc meta)))
1269 #:visibility STV_HIDDEN
1270 #:shndx (elf-section-index text-section)))))
1272 (let ((strtab (make-object asm '.strtab
1273 (link-string-table! strtab)
1275 #:type SHT_STRTAB #:flags 0)))
1276 (values (make-object asm '.symtab
1279 #:type SHT_SYMTAB #:flags 0 #:entsize size
1280 #:link (elf-section-index
1281 (linker-object-section strtab)))
1284 ;;; The .guile.arities section describes the arities that a function can
1285 ;;; have. It is in two parts: a sorted array of headers describing
1286 ;;; basic arities, and an array of links out to a string table (and in
1287 ;;; the case of keyword arguments, to the data section) for argument
1288 ;;; names. The whole thing is prefixed by a uint32 indicating the
1289 ;;; offset of the end of the headers array.
1291 ;;; The arity headers array is a packed array of structures of the form:
1293 ;;; struct arity_header {
1294 ;;; uint32_t low_pc;
1295 ;;; uint32_t high_pc;
1296 ;;; uint32_t offset;
1302 ;;; All of the offsets and addresses are 32 bits. We can expand in the
1303 ;;; future to use 64-bit offsets if appropriate, but there are other
1304 ;;; aspects of RTL that constrain us to a total image that fits in 32
1305 ;;; bits, so for the moment we'll simplify the problem space.
1307 ;;; The following flags values are defined:
1310 ;;; #x2: allow-other-keys?
1311 ;;; #x4: has-keyword-args?
1312 ;;; #x8: is-case-lambda?
1314 ;;; Functions with a single arity specify their number of required and
1315 ;;; optional arguments in nreq and nopt, and do not have the
1316 ;;; is-case-lambda? flag set. Their "offset" member links to an array
1317 ;;; of pointers into the associated .guile.arities.strtab string table,
1318 ;;; identifying the argument names. This offset is relative to the
1319 ;;; start of the .guile.arities section. Links for required arguments
1320 ;;; are first, in order, as uint32 values. Next follow the optionals,
1321 ;;; then the rest link if has-rest? is set, then a link to the "keyword
1322 ;;; indices" literal if has-keyword-args? is set. Unlike the other
1323 ;;; links, the kw-indices link points into the data section, and is
1324 ;;; relative to the ELF image as a whole.
1326 ;;; Functions with no arities have no arities information present in the
1327 ;;; .guile.arities section.
1329 ;;; Functions with multiple arities are preceded by a header with
1330 ;;; is-case-lambda? set. All other fields are 0, except low-pc and
1331 ;;; high-pc which should be the bounds of the whole function. Headers
1332 ;;; for the individual arities follow. In this way the whole headers
1333 ;;; array is sorted in increasing low-pc order, and case-lambda clauses
1334 ;;; are contained within the [low-pc, high-pc] of the case-lambda
1337 ;; Length of the prefix to the arities section, in bytes.
1338 (define arities-prefix-len 4)
1340 ;; Length of an arity header, in bytes.
1341 (define arity-header-len (* 6 4))
1343 ;; The offset of "offset" within arity header, in bytes.
1344 (define arity-header-offset-offset (* 2 4))
1346 (define-syntax-rule (pack-arity-flags has-rest? allow-other-keys?
1347 has-keyword-args? is-case-lambda?)
1348 (logior (if has-rest? (ash 1 0) 0)
1349 (if allow-other-keys? (ash 1 1) 0)
1350 (if has-keyword-args? (ash 1 2) 0)
1351 (if is-case-lambda? (ash 1 3) 0)))
1353 (define (meta-arities-size meta)
1354 (define (lambda-size arity)
1356 (* 4 ;; name pointers
1357 (+ (length (arity-req arity))
1358 (length (arity-opt arity))
1359 (if (arity-rest arity) 1 0)
1360 (if (pair? (arity-kw-indices arity)) 1 0)))))
1361 (define (case-lambda-size arities)
1363 arity-header-len ;; case-lambda header
1364 (map lambda-size arities))) ;; the cases
1365 (match (meta-arities meta)
1367 ((arity) (lambda-size arity))
1368 (arities (case-lambda-size arities))))
1370 (define (write-arity-headers metas bv endianness)
1371 (define (write-arity-header* pos low-pc high-pc flags nreq nopt)
1372 (bytevector-u32-set! bv pos low-pc endianness)
1373 (bytevector-u32-set! bv (+ pos 4) high-pc endianness)
1374 (bytevector-u32-set! bv (+ pos 8) 0 endianness) ; offset
1375 (bytevector-u32-set! bv (+ pos 12) flags endianness)
1376 (bytevector-u32-set! bv (+ pos 16) nreq endianness)
1377 (bytevector-u32-set! bv (+ pos 20) nopt endianness))
1378 (define (write-arity-header pos arity)
1379 (write-arity-header* pos (arity-low-pc arity)
1380 (arity-high-pc arity)
1381 (pack-arity-flags (arity-rest arity)
1382 (arity-allow-other-keys? arity)
1383 (pair? (arity-kw-indices arity))
1385 (length (arity-req arity))
1386 (length (arity-opt arity))))
1387 (let lp ((metas metas) (pos arities-prefix-len) (offsets '()))
1390 ;; Fill in the prefix.
1391 (bytevector-u32-set! bv 0 pos endianness)
1392 (values pos (reverse offsets)))
1394 (match (meta-arities meta)
1395 (() (lp metas pos offsets))
1397 (write-arity-header pos arity)
1399 (+ pos arity-header-len)
1400 (acons arity (+ pos arity-header-offset-offset) offsets)))
1402 ;; Write a case-lambda header, then individual arities.
1403 ;; The case-lambda header's offset link is 0.
1404 (write-arity-header* pos (meta-low-pc meta) (meta-high-pc meta)
1405 (pack-arity-flags #f #f #f #t) 0 0)
1406 (let lp* ((arities arities) (pos (+ pos arity-header-len))
1409 (() (lp metas pos offsets))
1411 (write-arity-header pos arity)
1413 (+ pos arity-header-len)
1415 (+ pos arity-header-offset-offset)
1418 (define (write-arity-links asm bv pos arity-offset-pairs strtab)
1419 (define (write-symbol sym pos)
1420 (bytevector-u32-set! bv pos
1421 (string-table-intern! strtab (symbol->string sym))
1422 (asm-endianness asm))
1424 (define (write-kw-indices pos kw-indices)
1425 ;; FIXME: Assert that kw-indices is already interned.
1426 (make-linker-reloc 'abs32/1 pos 0
1427 (intern-constant asm kw-indices)))
1428 (let lp ((pos pos) (pairs arity-offset-pairs) (relocs '()))
1431 (unless (= pos (bytevector-length bv))
1432 (error "expected to fully fill the bytevector"
1433 pos (bytevector-length bv)))
1435 (((arity . offset) . pairs)
1436 (bytevector-u32-set! bv offset pos (asm-endianness asm))
1437 (let ((pos (fold write-symbol
1439 (append (arity-req arity)
1442 ((arity-rest arity) => list)
1444 (match (arity-kw-indices arity)
1445 (() (lp pos pairs relocs))
1449 (cons (write-kw-indices pos kw-indices) relocs)))))))))
1451 (define (link-arities asm)
1452 (let* ((endianness (asm-endianness asm))
1453 (metas (reverse (asm-meta asm)))
1454 (size (fold (lambda (meta size)
1455 (+ size (meta-arities-size meta)))
1458 (strtab (make-string-table))
1459 (bv (make-bytevector size 0)))
1460 (let ((kw-indices-relocs
1463 (write-arity-headers metas bv endianness))
1464 (lambda (pos arity-offset-pairs)
1465 (write-arity-links asm bv pos arity-offset-pairs strtab)))))
1466 (let ((strtab (make-object asm '.guile.arities.strtab
1467 (link-string-table! strtab)
1469 #:type SHT_STRTAB #:flags 0)))
1470 (values (make-object asm '.guile.arities
1472 kw-indices-relocs '()
1473 #:type SHT_PROGBITS #:flags 0
1474 #:link (elf-section-index
1475 (linker-object-section strtab)))
1479 ;;; The .guile.docstrs section is a packed, sorted array of (pc, str)
1480 ;;; values. Pc and str are both 32 bits wide. (Either could change to
1481 ;;; 64 bits if appropriate in the future.) Pc is the address of the
1482 ;;; entry to a program, relative to the start of the text section, and
1483 ;;; str is an index into the associated .guile.docstrs.strtab string
1487 ;; The size of a docstrs entry, in bytes.
1488 (define docstr-size 8)
1490 (define (link-docstrs asm)
1491 (define (find-docstrings)
1492 (filter-map (lambda (meta)
1493 (define (is-documentation? pair)
1494 (eq? (car pair) 'documentation))
1495 (let* ((props (meta-properties meta))
1496 (tail (find-tail is-documentation? props)))
1498 (not (find-tail is-documentation? (cdr tail)))
1499 (string? (cdar tail))
1500 (cons (meta-low-pc meta) (cdar tail)))))
1501 (reverse (asm-meta asm))))
1502 (let* ((endianness (asm-endianness asm))
1503 (docstrings (find-docstrings))
1504 (strtab (make-string-table))
1505 (bv (make-bytevector (* (length docstrings) docstr-size) 0)))
1506 (fold (lambda (pair pos)
1509 (bytevector-u32-set! bv pos pc endianness)
1510 (bytevector-u32-set! bv (+ pos 4)
1511 (string-table-intern! strtab string)
1513 (+ pos docstr-size))))
1516 (let ((strtab (make-object asm '.guile.docstrs.strtab
1517 (link-string-table! strtab)
1519 #:type SHT_STRTAB #:flags 0)))
1520 (values (make-object asm '.guile.docstrs
1523 #:type SHT_PROGBITS #:flags 0
1524 #:link (elf-section-index
1525 (linker-object-section strtab)))
1529 ;;; The .guile.procprops section is a packed, sorted array of (pc, addr)
1530 ;;; values. Pc and addr are both 32 bits wide. (Either could change to
1531 ;;; 64 bits if appropriate in the future.) Pc is the address of the
1532 ;;; entry to a program, relative to the start of the text section, and
1533 ;;; addr is the address of the associated properties alist, relative to
1534 ;;; the start of the ELF image.
1536 ;;; Since procedure properties are stored in the data sections, we need
1537 ;;; to link the procedures property section first. (Note that this
1538 ;;; constraint does not apply to the arities section, which may
1539 ;;; reference the data sections via the kw-indices literal, because
1540 ;;; assembling the text section already makes sure that the kw-indices
1544 ;; The size of a procprops entry, in bytes.
1545 (define procprops-size 8)
1547 (define (link-procprops asm)
1548 (define (assoc-remove-one alist key value-pred)
1551 ((((? (lambda (x) (eq? x key))) . value) . alist)
1552 (if (value-pred value)
1554 (acons key value alist)))
1556 (acons k v (assoc-remove-one alist key value-pred)))))
1557 (define (props-without-name-or-docstring meta)
1559 (assoc-remove-one (meta-properties meta) 'name (lambda (x) #t))
1562 (define (find-procprops)
1563 (filter-map (lambda (meta)
1564 (let ((props (props-without-name-or-docstring meta)))
1566 (cons (meta-low-pc meta) props))))
1567 (reverse (asm-meta asm))))
1568 (let* ((endianness (asm-endianness asm))
1569 (procprops (find-procprops))
1570 (bv (make-bytevector (* (length procprops) procprops-size) 0)))
1571 (let lp ((procprops procprops) (pos 0) (relocs '()))
1574 (make-object asm '.guile.procprops
1577 #:type SHT_PROGBITS #:flags 0))
1578 (((pc . props) . procprops)
1579 (bytevector-u32-set! bv pos pc endianness)
1581 (+ pos procprops-size)
1582 (cons (make-linker-reloc 'abs32/1 (+ pos 4) 0
1583 (intern-constant asm props))
1587 ;;; The DWARF .debug_info, .debug_abbrev, .debug_str, and .debug_loc
1588 ;;; sections provide line number and local variable liveness
1589 ;;; information. Their format is defined by the DWARF
1593 (define (asm-language asm)
1594 ;; FIXME: Plumb language through to the assembler.
1597 ;; -> 5 values: .debug_info, .debug_abbrev, .debug_str, .debug_loc, .debug_lines
1598 (define (link-debug asm)
1599 (define (put-s8 port val)
1600 (let ((bv (make-bytevector 1)))
1601 (bytevector-s8-set! bv 0 val)
1602 (put-bytevector port bv)))
1604 (define (put-u16 port val)
1605 (let ((bv (make-bytevector 2)))
1606 (bytevector-u16-set! bv 0 val (asm-endianness asm))
1607 (put-bytevector port bv)))
1609 (define (put-u32 port val)
1610 (let ((bv (make-bytevector 4)))
1611 (bytevector-u32-set! bv 0 val (asm-endianness asm))
1612 (put-bytevector port bv)))
1614 (define (put-u64 port val)
1615 (let ((bv (make-bytevector 8)))
1616 (bytevector-u64-set! bv 0 val (asm-endianness asm))
1617 (put-bytevector port bv)))
1619 (define (put-uleb128 port val)
1621 (let ((next (ash val -7)))
1625 (put-u8 port (logior #x80 (logand val #x7f)))
1628 (define (put-sleb128 port val)
1630 (if (<= 0 (+ val 64) 128)
1631 (put-u8 port (logand val #x7f))
1633 (put-u8 port (logior #x80 (logand val #x7f)))
1634 (lp (ash val -7))))))
1636 (define (port-position port)
1637 (seek port 0 SEEK_CUR))
1639 (define (meta->subprogram-die meta)
1643 => (lambda (name) `((name ,(symbol->string name)))))
1646 (low-pc ,(meta-label meta))
1647 (high-pc ,(* 4 (- (meta-high-pc meta) (meta-low-pc meta)))))))
1649 (define (make-compile-unit-die asm)
1651 (@ (producer ,(string-append "Guile " (version)))
1652 (language ,(asm-language asm))
1654 (high-pc ,(* 4 (asm-pos asm)))
1656 ,@(map meta->subprogram-die (reverse (asm-meta asm)))))
1658 (let-values (((die-port get-die-bv) (open-bytevector-output-port))
1660 ((abbrev-port get-abbrev-bv) (open-bytevector-output-port))
1661 ;; (tag has-kids? attrs forms) -> code
1662 ((abbrevs) vlist-null)
1663 ((strtab) (make-string-table))
1664 ((line-port get-line-bv) (open-bytevector-output-port))
1667 ((files) vlist-null))
1669 (define (write-abbrev code tag has-children? attrs forms)
1670 (put-uleb128 abbrev-port code)
1671 (put-uleb128 abbrev-port (tag-name->code tag))
1672 (put-u8 abbrev-port (children-name->code (if has-children? 'yes 'no)))
1673 (for-each (lambda (attr form)
1674 (put-uleb128 abbrev-port (attribute-name->code attr))
1675 (put-uleb128 abbrev-port (form-name->code form)))
1677 (put-uleb128 abbrev-port 0)
1678 (put-uleb128 abbrev-port 0))
1680 (define (intern-abbrev tag has-children? attrs forms)
1681 (let ((key (list tag has-children? attrs forms)))
1682 (match (vhash-assoc key abbrevs)
1684 (#f (let ((code (1+ (vlist-length abbrevs))))
1685 (set! abbrevs (vhash-cons key code abbrevs))
1686 (write-abbrev code tag has-children? attrs forms)
1689 (define (intern-file file)
1690 (match (vhash-assoc file files)
1692 (#f (let ((code (1+ (vlist-length files))))
1693 (set! files (vhash-cons file code files))
1696 (define (write-sources)
1697 ;; Choose line base and line range values that will allow for an
1698 ;; address advance range of 16 words. The special opcode range is
1699 ;; from 10 to 255, so 246 values.
1703 (let lp ((sources (asm-sources asm)) (out '()))
1705 (((pc . s) . sources)
1706 (let ((file (assq-ref s 'filename))
1707 (line (assq-ref s 'line))
1708 (col (assq-ref s 'column)))
1710 ;; Guile line and column numbers are 0-indexed, but
1711 ;; they are 1-indexed for DWARF.
1713 (if file (intern-file file) 0)
1718 ;; Compilation unit header for .debug_line. We write in
1719 ;; DWARF 2 format because more tools understand it than DWARF
1720 ;; 4, which incompatibly adds another field to this header.
1722 (put-u32 line-port 0) ; Length; will patch later.
1723 (put-u16 line-port 2) ; DWARF 2 format.
1724 (put-u32 line-port 0) ; Prologue length; will patch later.
1725 (put-u8 line-port 4) ; Minimum instruction length: 4 bytes.
1726 (put-u8 line-port 1) ; Default is-stmt: true.
1728 (put-s8 line-port base) ; Line base. See the DWARF standard.
1729 (put-u8 line-port range) ; Line range. See the DWARF standard.
1730 (put-u8 line-port 10) ; Opcode base: the first "special" opcode.
1732 ;; A table of the number of uleb128 arguments taken by each
1733 ;; of the standard opcodes.
1734 (put-u8 line-port 0) ; 1: copy
1735 (put-u8 line-port 1) ; 2: advance-pc
1736 (put-u8 line-port 1) ; 3: advance-line
1737 (put-u8 line-port 1) ; 4: set-file
1738 (put-u8 line-port 1) ; 5: set-column
1739 (put-u8 line-port 0) ; 6: negate-stmt
1740 (put-u8 line-port 0) ; 7: set-basic-block
1741 (put-u8 line-port 0) ; 8: const-add-pc
1742 (put-u8 line-port 1) ; 9: fixed-advance-pc
1744 ;; Include directories, as a zero-terminated sequence of
1745 ;; nul-terminated strings. Nothing, for the moment.
1746 (put-u8 line-port 0)
1748 ;; File table. For each file that contributes to this
1749 ;; compilation unit, a nul-terminated file name string, and a
1750 ;; uleb128 for each of directory the file was found in, the
1751 ;; modification time, and the file's size in bytes. We pass
1752 ;; zero for the latter three fields.
1753 (vlist-for-each (match-lambda
1755 (put-bytevector line-port (string->utf8 file))
1756 (put-u8 line-port 0)
1757 (put-uleb128 line-port 0) ; directory
1758 (put-uleb128 line-port 0) ; mtime
1759 (put-uleb128 line-port 0) ; size
1762 (put-u8 line-port 0) ; 0 byte terminating file list.
1764 ;; Patch prologue length.
1765 (let ((offset (port-position line-port)))
1766 (seek line-port 6 SEEK_SET)
1767 (put-u32 line-port (- offset 10))
1768 (seek line-port offset SEEK_SET))
1770 ;; Now write the statement program.
1772 (define (extended-op opcode payload-len)
1773 (put-u8 line-port 0) ; extended op
1774 (put-uleb128 line-port (1+ payload-len)) ; payload-len + opcode
1775 (put-uleb128 line-port opcode))
1776 (define (set-address sym)
1777 (define (add-reloc! kind)
1779 (cons (make-linker-reloc kind
1780 (port-position line-port)
1784 (match (asm-word-size asm)
1787 (add-reloc! 'abs32/1)
1788 (put-u32 line-port 0))
1791 (add-reloc! 'abs64/1)
1792 (put-u64 line-port 0))))
1793 (define (end-sequence pc)
1794 (let ((pc-inc (- (asm-pos asm) pc)))
1795 (put-u8 line-port 2) ; advance-pc
1796 (put-uleb128 line-port pc-inc))
1798 (define (advance-pc pc-inc line-inc)
1799 (let ((spec (+ (- line-inc base) (* pc-inc range) 10)))
1801 ((or (< line-inc base) (>= line-inc (+ base range)))
1802 (advance-line line-inc)
1803 (advance-pc pc-inc 0))
1805 (put-u8 line-port spec))
1807 (put-u8 line-port 8) ; const-advance-pc
1808 (advance-pc (- pc-inc (floor/ (- 255 10) range))
1811 (put-u8 line-port 2) ; advance-pc
1812 (put-uleb128 line-port pc-inc)
1813 (advance-pc 0 line-inc)))))
1814 (define (advance-line inc)
1815 (put-u8 line-port 3)
1816 (put-sleb128 line-port inc))
1817 (define (set-file file)
1818 (put-u8 line-port 4)
1819 (put-uleb128 line-port file))
1820 (define (set-column col)
1821 (put-u8 line-port 5)
1822 (put-uleb128 line-port col))
1824 (set-address '.rtl-text)
1826 (let lp ((in out) (pc 0) (file 1) (line 1) (col 0))
1830 ;; There was no source info in the first place. Set
1831 ;; file register to 0 before adding final row.
1834 (((pc* file* line* col*) . in*)
1836 ((and (eqv? file file*) (eqv? line line*) (eqv? col col*))
1837 (lp in* pc file line col))
1839 (unless (eqv? col col*)
1841 (unless (eqv? file file*)
1843 (advance-pc (- pc* pc) (- line* line))
1844 (lp in* pc* file* line* col*)))))))))))
1846 (define (compute-code attr val)
1848 ('name (string-table-intern! strtab val))
1851 ('producer (string-table-intern! strtab val))
1852 ('language (language-name->code val))
1855 (define (exact-integer? val)
1856 (and (number? val) (integer? val) (exact? val)))
1858 (define (choose-form attr val code)
1860 ((string? val) 'strp)
1861 ((eq? attr 'stmt-list) 'sec-offset)
1862 ((exact-integer? code)
1864 ((< code 0) 'sleb128)
1865 ((<= code #xff) 'data1)
1866 ((<= code #xffff) 'data2)
1867 ((<= code #xffffffff) 'data4)
1868 ((<= code #xffffffffffffffff) 'data8)
1870 ((symbol? val) 'addr)
1871 (else (error "unhandled case" attr val code))))
1873 (define (add-die-relocation! kind sym)
1875 (cons (make-linker-reloc kind (port-position die-port) 0 sym)
1878 (define (write-value code form)
1880 ('data1 (put-u8 die-port code))
1881 ('data2 (put-u16 die-port code))
1882 ('data4 (put-u32 die-port code))
1883 ('data8 (put-u64 die-port code))
1884 ('uleb128 (put-uleb128 die-port code))
1885 ('sleb128 (put-sleb128 die-port code))
1887 (match (asm-word-size asm)
1889 (add-die-relocation! 'abs32/1 code)
1890 (put-u32 die-port 0))
1892 (add-die-relocation! 'abs64/1 code)
1893 (put-u64 die-port 0))))
1894 ('sec-offset (put-u32 die-port code))
1895 ('strp (put-u32 die-port code))))
1897 (define (write-die die)
1899 ((tag ('@ (attrs vals) ...) children ...)
1900 (let* ((codes (map compute-code attrs vals))
1901 (forms (map choose-form attrs vals codes))
1902 (has-children? (not (null? children)))
1903 (abbrev-code (intern-abbrev tag has-children? attrs forms)))
1904 (put-uleb128 die-port abbrev-code)
1905 (for-each write-value codes forms)
1907 (for-each write-die children)
1908 (put-uleb128 die-port 0))))))
1910 ;; Compilation unit header.
1911 (put-u32 die-port 0) ; Length; will patch later.
1912 (put-u16 die-port 4) ; DWARF 4.
1913 (put-u32 die-port 0) ; Abbrevs offset.
1914 (put-u8 die-port (asm-word-size asm)) ; Address size.
1916 (write-die (make-compile-unit-die asm))
1918 ;; Terminate the abbrevs list.
1919 (put-uleb128 abbrev-port 0)
1923 (values (let ((bv (get-die-bv)))
1924 ;; Patch DWARF32 length.
1925 (bytevector-u32-set! bv 0 (- (bytevector-length bv) 4)
1926 (asm-endianness asm))
1927 (make-object asm '.debug_info bv die-relocs '()
1928 #:type SHT_PROGBITS #:flags 0))
1929 (make-object asm '.debug_abbrev (get-abbrev-bv) '() '()
1930 #:type SHT_PROGBITS #:flags 0)
1931 (make-object asm '.debug_str (link-string-table! strtab) '() '()
1932 #:type SHT_PROGBITS #:flags 0)
1933 (make-object asm '.debug_loc #vu8() '() '()
1934 #:type SHT_PROGBITS #:flags 0)
1935 (let ((bv (get-line-bv)))
1936 ;; Patch DWARF32 length.
1937 (bytevector-u32-set! bv 0 (- (bytevector-length bv) 4)
1938 (asm-endianness asm))
1939 (make-object asm '.debug_line bv line-relocs '()
1940 #:type SHT_PROGBITS #:flags 0)))))
1942 (define (link-objects asm)
1943 (let*-values (;; Link procprops before constants, because it probably
1944 ;; interns more constants.
1945 ((procprops) (link-procprops asm))
1946 ((ro rw rw-init) (link-constants asm))
1947 ;; Link text object after constants, so that the
1948 ;; constants initializer gets included.
1949 ((text) (link-text-object asm))
1950 ((dt) (link-dynamic-section asm text rw rw-init))
1951 ((symtab strtab) (link-symtab (linker-object-section text) asm))
1952 ((arities arities-strtab) (link-arities asm))
1953 ((docstrs docstrs-strtab) (link-docstrs asm))
1954 ((dinfo dabbrev dstrtab dloc dline) (link-debug asm))
1955 ;; This needs to be linked last, because linking other
1956 ;; sections adds entries to the string table.
1957 ((shstrtab) (link-shstrtab asm)))
1959 (list text ro rw dt symtab strtab arities arities-strtab
1960 docstrs docstrs-strtab procprops
1961 dinfo dabbrev dstrtab dloc dline
1968 ;;; High-level public interfaces.
1971 (define* (link-assembly asm #:key (page-aligned? #t))
1972 "Produce an ELF image from the code and data emitted into @var{asm}.
1973 The result is a bytevector, by default linked so that read-only and
1974 writable data are on separate pages. Pass @code{#:page-aligned? #f} to
1975 disable this behavior."
1976 (link-elf (link-objects asm) #:page-aligned? page-aligned?))
1978 (define (assemble-program instructions)
1979 "Take the sequence of instructions @var{instructions}, assemble them
1980 into RTL code, link an image, and load that image from memory. Returns
1982 (let ((asm (make-assembler)))
1983 (emit-text asm instructions)
1984 (load-thunk-from-memory (link-assembly asm #:page-aligned? #f))))